An electricity supply management device has been known, in which a solar cell and a storage battery are combined. The electricity supply management device generates an electric power by using the solar cell during the daytime, supplies some of the generated power to one or more electric devices, supplies a surplus power to the storage battery to thereby charge the storage battery with the surplus power. During the nighttime, an electric power is discharged from the storage battery to be supplied to one or more electric devices (for example, Japanese Patent Application Publication No. 2004-023879).
Meanwhile, it is desired that solar energy is effectively used such that a power consumption by a load device is automatically and optimally adjusted to save the energy. In the meantime, in a conventional electricity supply management device, when the power consumption amount by a load device in a home exceeds the amount of solar power generated, a deficit in power is supplemented for by the power from a commercial AC power source. Accordingly, improvements are required to meet the above-described desires.